How to test keyboard latency
Tap test
Click the box, then tap any key quickly 30 times. We measure how long each press lasts and how fast the browser shows it on screen.
Roll test
Switch to step 2 and roll four fingers across A S D F as fast as you can. Fast overlapping presses reveal how often your keyboard reports.
Read the result
You get the estimated report rate, the key-to-frame time, your shortest and typical press, and a report you can download.
Use the same keyboard, cable or receiver and browser you play or type with. Close heavy apps first: background load adds delay of its own.
What this test measures, and what it cannot
Keyboard latency is the time from pressing a key to seeing the result on screen. It is built from several parts, and a web page can only see some of them:
Report rate
How often the keyboard sends key changes to the computer: every 8 ms at 125 Hz, every 1 ms at 1000 Hz. We estimate it from the spacing between fast key events.
- Delay it can add
- We measure it
Key to next frame
Time from the key event arriving in the browser to the next screen frame being drawn. This includes browser and system load.
- Delay it can add
- We measure it
Switch and debounce
The time inside the keyboard before it decides a key is pressed. It happens before any data leaves the keyboard.
- Delay it can add
- We measure it
Display
Your monitor’s refresh and response time. Only a high-speed camera can measure this part.
- Delay it can add
- We measure it
Other online tests show a single “latency” number without saying what starts and stops the timer. We show each part we can measure separately and say plainly what a browser cannot see.
How we estimate the report rate
A USB keyboard does not send each press the instant it happens. It collects changes and sends them in reports at a fixed interval. When two keys change in different reports, the time between them is a whole multiple of that interval. During the roll test we collect many short gaps between key events and find the largest interval that explains almost all of them: 8 ms means 125 Hz, 4 ms means 250 Hz, 2 ms means 500 Hz, and anything finer is reported as 1000 Hz or faster.
Browser timestamps are slightly rounded and the operating system adds a little noise, so the result comes with a confidence level. Low confidence simply means the test needs more fast key events: keep rolling until the counter fills.
Reading your result
1000 Hz or faster, under 12 ms to frame
Typical of a gaming keyboard on a responsive computer. The keyboard itself adds about 1 ms.
125 Hz, or 12–25 ms to frame
Normal for office keyboards and 60 Hz screens. Fine for typing; competitive players may notice the extra few milliseconds.
Over 25 ms to frame
Something on the computer is adding delay: heavy background load, power saving, or a remote desktop session.
Your shortest and typical press times describe your typing, not your keyboard. Most people hold a quick tap for 60 to 120 ms. Very short presses, under 30 ms, usually come from fast rolls or optical and Hall effect switches with rapid trigger.
How to reduce keyboard input lag
- Use a wired connection or the keyboard’s own receiverBluetooth usually adds more delay than a 2.4 GHz receiver or a cable.Free
- Raise the report rateMany gaming keyboards ship at 125 or 500 Hz. Set 1000 Hz in the keyboard software, then run the roll test again to confirm.Free
- Plug into the computer directlyAvoid unpowered hubs and monitor USB ports for gaming keyboards.Free
- Lower debounce or enable rapid triggerIf your keyboard software offers it. Too low a debounce can cause double typing: check with our keyboard double click test.Free
- Use a faster screenA 144 Hz or faster monitor cuts the frame part of the delay by more than half.$$